Amazing new laser could diagnose disease and detect greenhouse gases

Researchers have created a laser powerful enough to detect minute concentrations of gases in the atmosphere or in your mouth.

Now here's a bright idea: Researchers at the University of Adelaide in Australia have created an amazing new kind of laser that is powerful enough to detect minute concentrations of gases. Pointed at your mouth, the laser could help to diagnose diseases by analyzing the components of your breath. Pointed at the atmosphere, the laser could help to identify concentrations of the greenhouse gases that are causing climate change.

Those are just two of the myriad possible uses of this new laser, details for which were published recently in the journal Optics Letters.

The laser — which was developed by researchers from the university's Institute for Photonics and Advanced Sensing and its School of Chemistry and Physics — operates in the mid-infrared range at a frequency range in which hydrocarbon gases absorb light. Plenty of other lasers operate at this frequency, but this one is much more powerful. It is also smaller and less expensive. "This laser has significantly more power and is much more efficient than other lasers operating in this frequency range," researcher Ori Henderson-Sapir said in a press release. They achieved this extra power (along with the cost savings) by creating a erbium-doped zirconium-fluoride-based glass fiber, which is said to be the first of its kind. "Using a novel approach," Henderson-Sapir said, "we've been able to overcome the significant technical hurdles that have prevented fiber lasers from producing sufficient power in the mid-infrared."

Project leader David Ottaway said this added power boost allows them to detect gases at extremely low levels. "For instance, it should enable the possibility of analyzing trace gases in exhaled breath in the doctors' surgery." As the press release points out, one disease that can be detected by the breath is diabetes. Asthma, kidney disease and high cholesterol are also routinely detected by analyzing exhaled gases, but as Scientific American reported last year the devices that do so use sensors, gas chromatography or mass spectroscopy and can cost upwards of $30,000.

Outside of the doctor's office, the researchers say their new laser could also be used to detect gases such as methane and ethane in the atmosphere. Both are extremely potent greenhouse gases but do not need to be present at great quantities to have their world-warming effect. Detecting where these gases are escaping into the atmosphere could help to slow their effect on the global system.

There is no word yet on when this new kind of laser could be commercialized.